Field of the Invention
The invention relates to a semiconductor device with function for generating unique information, and more particularly to a method for generating unique information by circuit elements of a semiconductor device.
Description of the Related Art
In recent years, with the strengthening of the security of semiconductor devices and electronic devices, countermeasures against counterfeiting and cloning of semiconductor devices mounted thereon are required. In one method, unique information is given to a semiconductor device, and when the unique information is authenticated, the semiconductor device is considered as an authentic object, and the semiconductor device or the electronic device is allowed to operate. The unique information can be stored in, for example, a non-volatile memory of a semiconductor device or the like. However, with this method, there is risk that the unique information can be read by analyzing the semiconductor device or by illegally accessing the semiconductor device from the outside.
Therefore, in recent years, PUF (Physical Unclonable Function) technology has attracted attention, wherein physical copying is not allowed. PUF technology uses unpredictable physical information with high confidentiality and permanency as unique information. For example, Patent Document 1 (Japanese Patent Publish No. 2015-80252) discloses a digital value generating apparatus and method for generating unique digital values according to process variations of semiconductor elements thereof. Patent Document 2 (Japanese Patent Publish No. 2016-12931) discloses a semiconductor device in which unique information is read from a memory region corresponding to a unique code of a specific element generated by a peculiar-code generation portion.